More specifically, we tested the following three hypotheses. First, we predicted that an alcohol dependence continuum could be derived from measures of alcohol use by applying IRT methods to markers selected to be consistent with Jellinek’s developmental theory. Second, we hypothesized that this continuum would increment the validity of additive measures of alcohol use in predicting clinically-relevant criteria. Third, we hypothesized that traitedness on this continuum would moderate its validity in predicting external criteria including treatment response, meaning that severity would prove to be a more powerful predictor of outcome in a group of individuals with alcohol problems when they demonstrate a pattern of alcohol involvement that is consistent with a developmental progression of increasing alcohol dependence.
